Fullback Jorvorskie Lane #41 of the Miami Dolphins reacts after scoring on a 1 yard rushing touchdown against the Arizona Cardinals during the second quarter of the NFL game at the University of Phoenix Stadium on September 30, 2012 in Glendale, Arizona. (Photo by Christian Petersen/Getty Images)

(Photo by Christian Petersen/Getty Images)

MIAMI (CBSMiami) – The Miami Dolphins offense continues to exceed expectations week in and week out in 2012, but even with the vast improvements from both the offensive line and the quarterback position, there is one aspect that is sticking in the craw of offensive coordinator Mike Sherman.

“We have to be much better there [short-yardage offense],” Sherman said. “I think it’s a matter of repetition in practice. I think there’s no excuse for us not to be able to get a yard.”

Miami has struggled in third down and short yardage this season, even when the defense gives the Dolphins prime field position.

“We’ve had great opportunities,” Sherman said. “We had great field position that we don’t take advantage of. The defense gave us great field position and then we third and one, fourth and one and we’re done. That’s unacceptable, but we’ll get that fixed I promise you.”

Sherman was asked this week to pinpoint the area of the offense that has improved the most since Week 1 and he echoed what many fans have been saying, quarterback Ryan Tannehill.

“He just keeps getting better and better,” Sherman said. “Very seldom does he make the same mistake twice. You tell him that you need to do this and he does it. So I think his maturation throughout the course of the NFL season, going into Week 6, he has taken steps every single week. He will continue to do that throughout the course of the season and the course of his career.”

While Tannehill has improved, his offensive line deserves some of the credit for giving him time in the pocket. The Dolphins were confident about the ability of the left side of the offensive line with Pro Bowl left tackle Jake Long, guard Richie Incognito, and center Mike Pouncey.

But, the right side of the offensive line features guard John Jerry who has underperformed in recent years and rookie right tackle Jonathan Martin. Despite their youth, both have performed well thus far on the season.

“I think Jonathan Martin, for a rookie, is playing above our expectations at this point,” Sherman said. “He’s not perfect by any stretch of the imagination, but he is excellent with his hands and he takes pretty good pass sets for the most part.”

Sherman continued, “John Jerry, and I have to give Coach Turner a lot of credit for this, being on John about losing his weight. He’s lost 30-35 pounds since the summer time and I think that’s really added to his game. Both players aren’t perfect. They still have a ways to go, but I think we’re getting there.”

The Dolphins will send its much-improved offense on the field Sunday against the St. Louis Rams.